Progressive fine filtration for a dishwashing appliance

ABSTRACT

A filtering system is provided for a dishwashing appliance that can remove fine particles from the wash and rinse fluids. The system uses a filter that can be rotated between filter media that are equipped for removal of different particulate sizes depending upon e.g., the cycle or stage of the cleaning process and/or anticipated particle size. The filter cartridge is positioned upstream from the pump inlet. In certain embodiments, the filter cartridge can be removable for servicing. In certain embodiments, all fluid received from the wash chamber can be passed through the fine filter so as to improve the removal of smaller particles from the wash or rinse fluids.

FIELD OF THE INVENTION

The subject matter of the present disclosure relates generally to filtration of the wash and/or rinse fluids in a dishwashing appliance.

BACKGROUND OF THE INVENTION

During wash and rinse cycles, dishwashers typically circulate a fluid through a wash chamber over articles such as pots, pans, silverware, and other cooking utensils. The fluid can be e.g., various combinations of water and detergent during the wash cycle or water (which may include additives) during the rinse cycle. Typically, the fluid is recirculated during a given cycle using a pump. Fluid is collected at or near the bottom of the wash chamber and pumped back into the chamber through e.g., nozzles in the spray arms and other openings that direct the fluid against the articles to be cleaned or rinsed. Fluids used in e.g., the wash or rinse cycles may be heated. For example, hot water may be supplied to the dishwasher and/or the dishwasher may include one or more heat sources (e.g., electrically-resistant heating elements) for heating fluids used in the wash or rinse cycle and for providing heat during a drying cycle.

Depending upon the level of soil upon the articles, fluids used during wash and rinse cycles will become contaminated with soils in the form of debris or particles. To protect the pump and recirculate the fluid through the wash chamber, it is beneficial to filter the fluid so that relatively clean fluid is applied to the articles in the wash chamber and materials are removed or reduced from the fluid supplied to the pump.

For mechanical filtration, the selectivity of the filter to remove soil particles of different sizes is typically determined by providing fluid paths (such as pores or apertures) through a filter media that are smaller than the particles for which filtration is desired. Particles having a dimension larger than the width of the fluid paths will be trapped or prevented from passing through the filter while particles smaller than the width of the fluid path will generally pass through. Some particle sizes and/or types may be not harmful to the pump or spray assemblies and, therefore, can be allowed to pass into the pump inlet. However, while some smaller particles may not be harmful to the pump, leaving such particles in the wash or rinse fluid may not be acceptable as these particles may become deposited on the articles being washed/rinsed and thereby affect the user's perception of the cleanliness and/or appearance.

While larger particles can generally be readily removed from the fluid circulated through the wash chamber, challenges are presented in removing smaller particles—particularly as the particle size targeted for removal decreases. For example, if a dishwashing appliance is provided with a fine particle filter—such as one for removing particles 200 microns or larger—the filter can be prone to clogging, particularly during the early stages of the cleaning process. During a pre-wash cycle or an early stage of a wash cycle, a greater amount of larger food particles may be present on the articles placed in the wash chamber. A fine particle filter—such as one for removing particles 200 microns or larger—may become substantially clogged.

To unclog the filter, a conventional approach has been to drain the dirty fluid from the wash chamber to remove the particles clogging the filter. New—i.e., clean fluid—is then reintroduced for cycling. Depending on the level of soil still present on the articles, yet another cycle of draining and refilling may have to be performed. Unfortunately, this run, drain, and refill approach for unclogging a filter is inefficient as it requires the use of additional fluid (i.e., water) and, when the fluid is heated, additional energy is consumed as the fluid is drained and the new water is reheated. Of course, a filter media can be selected that only captures larger particles so that it clogs less, such as e.g., 0.030″ or larger, but this comes at the expense of losing the ability to remove smaller particles from the fluid and an associated effect on the resulting cleanliness of the articles.

Another challenge with filtration of the wash fluid is servicing of the filter and, more particularly, the filter media. Sometimes, for example, food particles can become lodged in the filter, requiring that the filter be removed and either manually cleaned or replaced. Certain conventional dishwashing appliances do not have a filter that is readily accessible to the user and/or otherwise readily cleanable or serviceable.

Finally, because of the previously mentioned problems with filter clogging, certain dishwashing appliances may provide fine filtration with a by-pass through a coarse filter. For example, even when fine filtering is provided, the dishwashing appliance may simultaneously pass fluid through both a coarse filter and a fine filter. As such, only a portion of fluid from the wash chamber is subjected to filtering through the fine filter before recirculation to the wash chamber. While this configuration can be advantageous, the ability to circulate all fluid through a fine filter before recirculating to the wash chamber would more effectively remove small particles from the fluid—if such can be accomplished without clogging.

Accordingly, a dishwasher appliance having filtering system for the removal of particles from the wash fluid would be useful. More particularly, a filtering system that can remove both large and fine particles (e.g., 50 to 100 micron or larger) without repeated draining and refilling to unclog the filter would be particularly beneficial. A filtering system that can also effectively use a fine filter to filter all of the fluid received from the wash chamber during recirculation would also be useful. Such a filtering system using a filter that can also be readily accessed and serviced would also be useful.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a filtering system for a dishwashing appliance that can remove fine particles from the wash and rinse fluids. A filter is provided that can be rotated between filter media that are equipped for removal of different particulate sizes depending upon e.g., the cycle or stage of the cleaning process and/or anticipated particle size. The filter cartridge is positioned upstream from the pump inlet. In certain embodiments, the filter cartridge can be removable for servicing. In certain embodiments, all fluid received from the wash chamber can be passed through the fine filter so as to improve the removal of smaller particles from the wash or rinse fluids. Additional aspects and advantages of the invention will be set forth in part in the following description, may be apparent from the description, or may be learned through practice of the invention.

In a first exemplary embodiment, the present invention provides a dishwashing appliance with a wash chamber having a sump portion. A receptacle is located in the sump portion. The receptacle defines an interior surface and a fluid outlet. A pump is in fluid communication with the sump portion of the wash chamber to receive fluid from the wash chamber. A first filter is positioned in the sump portion and is configured for the receipt of fluid circulated through the wash chamber. A rotatable, second filter is positioned within the receptacle and is configured for the receipt of fluid circulated through the wash chamber. The second filter defines a radial direction, axial direction, and circumferential direction. The second filter is rotatable along the circumferential direction within the receptacle and includes a cylindrically-shaped wall forming an internal chamber. The wall includes a first filter media positioned along the cylindrically-shaped wall; a first axial seal and a second axial seal, each extending along the axial direction and each extending radially from the cylindrically-shaped wall of the second filter towards the interior wall of the receptacle; and at least one circumferential seal extending circumferentially between the first axial seal and the second axial seal. The second filter is rotatable between i) a first position in which fluid from the wash chamber filters simultaneously through both the first filter and the second filter to flow to the pump and ii) a second position in which the seals surround the fluid outlet of the receptacle so that fluid from the wash chamber filters only through the second filter to flow to the pump.

In another exemplary embodiment, the present invention provides a dishwashing appliance that includes a wash chamber having a sump portion. A receptacle is located in the sump portion. The receptacle defines an interior wall and a fluid outlet. A pump is in fluid communication with the sump portion of the wash chamber to receive fluid from the wash chamber. A rotatable filter is positioned within the receptacle and is configured for the receipt of fluid circulated through the wash chamber. The filter defines a radial direction, axial direction, and circumferential direction. The filter is rotatable along the circumferential direction within the receptacle. The filter includes a cylindrically-shaped wall forming an internal chamber and comprising a first filter media, a second filter media, and a third filter media all positioned along the cylindrically-shaped wall and adjacent to each other along the circumferential direction. The filter also includes a first axial seal, a second axial seal, and a third axial seal, each extending along the axial direction and each extending radially from the cylindrically-shaped wall of the filter towards the interior wall of the receptacle. The filter also includes a first circumferential seal extending circumferentially between the first axial seal and the second axial seal; a second circumferential seal extending circumferentially between the second axial seal and the third axial seal; and a third circumferential seal extending circumferentially between the second axial seal and the third axial seal. The filter is rotatable between i) a first position in which the fluid from the wash chamber filters only through the first filter media to flow to the pump; ii) a second position in which fluid from the wash chamber filters only through the second filter media to flow to the pump; and iii) a third position in which fluid from the wash chamber filters only through the third filter media to flow to the pump.

In still another exemplary embodiment, the present invention provides a dishwashing appliance that includes a wash chamber having a sump portion. A receptacle is located in the sump portion. The receptacle defines an interior wall and a fluid outlet. A pump is in fluid communication with the sump portion of the wash chamber to receive fluid from the wash chamber. A first filter is positioned in the sump portion and is configured for the receipt of fluid circulated through the wash chamber. A rotatable, second filter is positioned within the receptacle and is configured for the receipt of fluid circulated through the wash chamber. The second filter defines a radial direction, axial direction, and circumferential direction. The second filter is rotatable along the circumferential direction within the receptacle. The second filter includes a cylindrically-shaped wall forming an internal chamber and having a first filter media, a second filter media, and a third filter media positioned along the cylindrically-shaped wall. The second filter also includes a first axial seal and a second axial seal, each extending along the axial direction and each extending radially from the cylindrically-shaped wall of the second filter towards the interior wall of the receptacle. The second filter also includes at least one circumferential seal extending circumferentially between the second axial seal and the third axial seal. The second filter is rotatable between i) a first position in which fluid from the wash chamber filters simultaneously through both the first filter and the first filter media to flow to the pump; ii) a second position in which fluid from the wash chamber filters simultaneously through both the first filter and the second filter media to flow to the pump; and iii) a third position in which fluid from the wash chamber flows only through the third filter media to flow to the pump.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 is front view of an exemplary embodiment of a dishwashing appliance of the present invention.

FIG. 2 is a side view of an exemplary embodiment of a dishwashing appliance of the present invention.

FIG. 3 is a front view showing the inside of a dishwashing appliance of the present invention. A grate or first filter has been removed to reveal a recess in a sump portion of the wash chamber.

FIG. 4 provides an exploded view of an exemplary embodiment of a filter system of the present invention.

FIG. 5 is a perspective view of certain parts of an exemplary filter system of the present invention.

FIGS. 6 and 7 are top, cross-sectional views of the exemplary filter system of FIG. 4.

FIG. 8 is a side, cross-sectional view of the exemplary filter system of FIG. 4 in a first position.

FIG. 9 is a side, cross-sectional view of the exemplary filter system of FIG. 4, albeit with the second filter rotated to a second, different position than FIG. 8.

FIGS. 10, 11, and 12 are top, cross-sectional views of another exemplary embodiment of a filter system of the present invention.

FIG. 13 is a perspective view of certain parts of the exemplary filter system of FIGS. 10, 11, and 12.

FIGS. 14, 15, and 16 are top, cross-sectional views of another exemplary embodiment of a filter system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the term “article” may refer to, but need not be limited to, dishes, pots, pans, silverware, and other cooking utensils and items that can be cleaned in a dishwashing appliance. The term “wash cycle” is intended to refer to one or more periods of time during the cleaning process where a dishwashing appliance operates while containing articles to be washed and uses a detergent and water, preferably with agitation, to e.g., remove soil particles including food and other undesirable elements from the articles. The term “rinse cycle” is intended to refer to one or more periods of time during the cleaning process in which the dishwashing appliance operates to remove residual soil, detergents, and other undesirable elements that were retained by the articles after completion of the wash cycle. The term “drying cycle” is intended to refer to one or more periods of time in which the dishwashing appliance is operated to dry the articles by removing fluids from the wash chamber. The term “fluid” refers to a liquid used for washing and/or rinsing the articles and is typically made up of water that may include additives such as e.g., detergent or other treatments. As used herein, “fluidly connected” or “in fluid communication with” and the like means that fluid can flow between the identified elements that may be directly connected or may be connected through other components to allow fluid to flow therethrough.

FIGS. 1 and 2 depict an exemplary domestic dishwasher 100 that may be configured in accordance with aspects of the present disclosure. For the particular embodiment of FIGS. 1 and 2, the dishwasher 100 includes a cabinet 102 having a tub 104 therein that defines a wash chamber 106. The tub 104 includes a front opening (not shown) and a door 120 hinged at its bottom 122 for movement between a normally closed vertical position (shown in FIGS. 1 and 2), wherein the wash chamber 106 is sealed shut for washing operations, and a horizontal open position for loading and unloading of articles from the dishwasher. Latch 156 is used to lock and unlock door 120 for access to wash chamber 106.

Upper and lower guide rails 124, 126 are mounted on tub side walls 128 and accommodate roller-equipped rack assemblies 130 and 132. Each of the rack assemblies 130, 132 is fabricated into lattice structures including a plurality of elongated members 134 (for clarity of illustration, not all elongated members making up assemblies 130 and 132 are shown in FIG. 2). Each rack 130, 132 is adapted for movement between an extended loading position (not shown), in which the rack is substantially positioned outside the wash chamber 106, and a retracted position (shown in FIGS. 1 and 2), in which the rack is located inside the wash chamber 106. This rack movement is facilitated by rollers 135 and 139, for example, mounted onto racks 130 and 132, respectively. A silverware basket (not shown) may be removably attached to rack assembly 132 for placement of silverware, utensils, and the like that are otherwise too small to be accommodated by the racks 130, 132.

The dishwasher 100 further includes a lower spray-arm assembly 144 that is rotatably mounted within a lower region 146 of the wash chamber 106 and above a tub sump portion 142 so as to rotate in relatively close proximity to rack assembly 132. A mid-level spray-arm assembly 148 is located in an upper region of the wash chamber 106 and may be located in close proximity to upper rack 130. Additionally, an upper spray assembly 150 may be located above the upper rack 130.

The lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150 are part of a fluid circulation assembly 152 for circulating water and dishwasher fluid in the tub 104. The fluid circulation assembly 152 also includes a recirculation pump 154 positioned in a machinery compartment 140 located below the tub sump portion 142 (i.e., bottom wall) of the tub 104, as generally recognized in the art. Pump 154 receives fluid from sump 142 to provide a flow to assembly 152, or optionally, a switching valve or diverter (not shown) may be used to select flow. A heating element 170 can be used to provide heat during e.g., a drying cycle.

Each spray-arm assembly 144, 148 includes an arrangement of discharge ports or orifices for directing washing fluid received from pump 154 onto dishes or other articles located in rack assemblies 130 and 132. The arrangement of the discharge ports in spray-arm assemblies 144, 148 provides a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of the spray-arm assemblies 144, 148 and the operation of spray assembly 150 using fluid from pump 154 provides coverage of dishes and other dishwasher contents with a washing spray. Other configurations of spray assemblies may be used as well.

The dishwasher 100 is further equipped with a controller 137 to regulate operation of the dishwasher 100. The controller may include one or more memory devices and one or more microprocessors, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.

The controller 137 may be positioned in a variety of locations throughout dishwasher 100. In the illustrated embodiment, the controller 137 may be located within a control panel area 121 of door 120 as shown in FIGS. 1 and 2. In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher 100 along wiring harnesses that may be routed through the bottom 122 of door 120. Typically, the controller 137 includes a user interface panel/controls 136 through which a user may select various operational features and modes and monitor progress of the dishwasher 100. In one embodiment, the user interface 136 may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface 136 may include input components, such as one or more of a variety of electrical, mechanical, or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface 136 may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. The user interface 136 may be in communication with the controller 137 via one or more signal lines or shared communication busses.

It should be appreciated that the invention is not limited to any particular style, model, or configuration of dishwasher. The exemplary embodiment depicted in FIGS. 1 and 2 is for illustrative purposes only. For example, different locations may be provided for user interface 136, different configurations may be provided for racks 130, 132, and other differences may be applied as well.

Referring now to FIGS. 2, 3, and 4, an exemplary filtering system 200 is located in sump portion 142 and provides filtered fluid to pump inlet 162. Filtering system 200 removes soiled particles from the fluid that is recirculated through the wash chamber 106 during operation of dishwasher 100. For this exemplary embodiment, filtering system 200 includes both a first filter 202 (also referred to as a “coarse filter”) and a second filter 204 (also referred to as a “fine filter”). In certain other embodiments of the present invention, dishwasher 100 may not include filter 202 and, instead, may include only filter 204 having a plurality of different filter media as further described below.

Based on the shape of sump portion 142 (see FIG. 2), fluid flows down along vertical direction V to filtering system 200 for filtration. After the fluid is filtered by passing through first filter 202 (e.g., a coarse filter) or second filter 204 (e.g., a fine filter), the filtered fluid is fed to the inlet 162 of pump 154 for return to the wash chamber 106 by way of fluid circulation assembly 152. After being sprayed onto articles in the dishwashing appliance using one or more of spray elements 144, 148, and 150, the fluid eventually flows to sump portion 142 and is filtered again.

Filtered waste material can be removed from filter assembly 200 by a drain pump 208 feeding drain 210. Accordingly, filtering system 200 acts to clean soil particles from the fluid so as to e.g., protect pump 154 and/or the spray assemblies from clogging as the fluid is recirculated during the cleaning process of the dishwashing appliance 100 such as e.g., a wash or rinse cycle of appliance 100. The filtering system can also provide a cleaner fluid during the cleaning process, which results in cleaner articles.

For this exemplary embodiment, first filter 202 is constructed as a grate having openings 218 for filtering fluid received from wash chamber 106. Sump portion 142 includes a recessed portion 216 over which first filter 202 is removably received. In one exemplary embodiment, first filter 202 operates as a coarse filter having openings 218 in the range of about 0.030 inches to about 0.060 inches. Second filter 204 can be non-removable or can be provided as a removable cartridge positioned in a cylindrically-shaped receptacle 212 formed in sump portion 142. A handle 214 on second filter 204 allows a user to grasp and remove second filter 204 for replacement or cleaning. Opening 222 allows for positioning of second filter 204 into receptacle 212.

Referring now to FIG. 5, second filter 204 is rotatable within receptacle 212 along circumferential direction C. A motor 234 drives a gear 238 by shaft 236, which in turn rotates second filter 204 using gear 240 that extends circumferentially about the bottom 232 of second filter 204. Controller 137 can be used to position second filter 204 into the position desired during cleaning operations of appliance 100. Other configurations for selectively rotating second filter 204 may be use as well.

As shown in FIGS. 6 and 7, for this exemplary embodiment, second filter 204 is rotatable between a first position shown in FIG. 6 and a second position shown in FIG. 7. In the first position shown in FIG. 6, fluid from wash chamber 106 filters simultaneously through both the first filter 202 and the second filter 204. In the second position shown in FIG. 7, fluid from wash chamber 106 filters only through the second filter 204. Features allowing the selection of filtering in either the first position or second position of second filter 204 will now be further described.

Referring to FIG. 8, when second filter 204 is in the first position as shown, filtering through system 200 includes a flow CF through the first filter 202 and a flow FF through the second filter 204. More particularly, openings 228 in the top 220 of second filter 204 provide a fluid inlet to allow fluid FF to flow into an internal chamber 224 defined by a cylindrically-shaped wall 226 of second filter 204. Fluid FF is fluid from wash chamber 106 that flows over the top of the first filter 202 without passing through its openings 218 for coarse filtration. From internal chamber 224, fluid FF can flow through a fine filter media 230 forming wall 226 whereby even smaller particulates P are removed from fluid FF. Drain pump 208 can be used to remove particulate-laden fluid PF from chamber 224.

After passing through filter media 230, when second filter 204 is in the first position, fluid FF combines with fluid CF that has been filtered by first filter 202 by passing through openings 218 therein. These fluids are combined within a small annulus or gap 268 between interior surface 250 of receptacle 212 and the cylindrically-shaped wall 226 of second filter 204. The combined flow of filtered fluid F exits receptacle 212 through fluid outlet 242 to pump inlet 162. Pump 154 then returns filtered fluid F to the wash chamber 106 through assembly 152 as previously described. As stated, during this first position for operation of filtering system 200, fluid from wash chamber 106 passes through both the first filter 202 and second filter 204.

To provide flow that is filtered only though second filter 204 when rotated to the second position, second filter 204 is equipped with a first axial seal 244, a second axial seal 246, and a circumferential seal 248 as shown in FIGS. 5, 7, and 9. First and second axial seals 244 and 246 each extend longitudinally along the axial direction A and have a width that extends along radial direction R towards interior surface 250 of receptacle 212. Circumferential seal 248 extends along circumferential direction C between first axial seal 244 and second axial seal 246 at the top 220 of second filter 204. Thus, a portion of filter media 230 of second filter 204 is surrounded on three sides by seals 244, 246, and 248. When in the second position, first and second axial seals 244 and 246 each contact the interior surface 250 of receptacle 212 (unlike the first position shown in FIG. 6). This contact between seals 244, 246 and interior surface 250 provides a fluid seal.

As shown in FIGS. 7 and 9, when in the second position, first and second axial seals 244 and 246 and circumferential seal 248 surround fluid outlet 242 of receptacle 212. By way of comparison, when in the first position shown in FIG. 6, seals 244, 246, and 248 do not surround fluid outlet 242. In the second position, circumferential seal 248 contacts interior surface 250 and blocks the flow of fluid CF from the first filter 202 through a fluid passageway 252 defined by first filter 202 and sump portion 142. Axial seals 244 and 246 also prevent the flow of fluid CF from the coarse filter.

As such, when in the second position, fluid from wash chamber 106 can only flow through the filter media 230 of second filter 204 and, more particularly, only through the portion of filter media 230 surrounded by seals 244, 246, and 248. By providing filter media 230 as a fine filter, dishwashing appliance 100 can thereby operate in a mode where all fluid recirculated to the wash chamber is filtered through a fine filter media 230 of second filter 204. For example, controller 137 might cause motor 234 to rotate second filter 204 to the first position during a wash cycle when larger particulates are predominantly present and to the second position during a rinse cycle when less and/or smaller particulates are predominantly present in the fluid circulated through wash chamber 106.

In one exemplary embodiment, filter media 230 might be configured with filter openings or pore sizes in the range of about 300 microns to about 600 microns. In still another embodiment, filter media 230 might be configured with filter openings or pore sizes in the range of about 50 microns to 150 microns.

FIGS. 10, 11, 12, and 13 illustrate another exemplary embodiment of the invention in which filter system 200 is provided with the ability to select for flow through a plurality of different filter media. More particularly, for this exemplary embodiment, filtering system 200 includes a filter 204 positioned within receptacle 212 and rotatable about circumferential direction C as previously described. Filter 204 includes a first filter media 256, a second filter media 258, and a third filter media 260 that are all positioned along cylindrically-shaped wall 226 and adjacent to each other along circumferential direction C.

Filter 204 also includes a first axial seal 244, a second axial seal 246, and a third axial seal 254. Each axial seal extends longitudinally along the axial direction A and have a width that extends along radial direction R towards interior surface 250 of receptacle 212. Filter 204 also includes a first circumferential seal 262, a second circumferential seal 264, and a third circumferential seal 266—where each seal is positioned at the top 220 of second filter 204.

First circumferential seal 262 extends along circumferential direction C between first axial seal 244 and second axial seal 246 so that these three seals surround first filter media 256. In addition, when filter 204 is rotated into the first position shown in FIG. 10, seals 244, 246, and 262 surround fluid outlet 242 of receptacle 212. Contact between seals 244, 246, 262 and interior surface 250 of receptacle 212 as shown in FIG. 10 provides fluid sealing that ensures fluid flow—i.e. filtering—is only through first filter media 256. More particularly, fluid received from wash chamber 106 flows into the internal chamber 224 of filter 204 to pass radially outward through only first filter media 256 before exiting through fluid outlet 242 for flow to pump 154. In one exemplary embodiment of the invention, first filter media 256 includes a filter media having pore or hole sizes in the range of about 0.030 inches to about 0.060 inches. Other sizes may be used as well. As such, unlike the previously described embodiment in FIGS. 4 through 9, the embodiment of FIGS. 10 through 13 may not require a coarse filter 202.

Continuing with FIGS. 10 through 13, second circumferential seal 264 extends along circumferential direction C between second axial seal 246 and third axial seal 254 so that these three seals surround second filter media 258. In addition, when filter 204 is rotated into the second position shown in FIG. 11, seals 246, 254, and 264 surround fluid outlet 242 of receptacle 212. Contact between seals 246, 254, 264 and interior surface 250 of receptacle 212 as shown in FIG. 11 provides fluid sealing that ensures fluid flow—i.e., filtering—is only through second filter media 258. More particularly, fluid received from wash chamber 106 flows into the internal chamber 224 of filter 204 to pass radially outward through only second filter media 258 before exiting through fluid outlet 242 for flow to pump 154. In one exemplary embodiment of the invention, second filter media 258 includes a filter media having pore or hole sizes in the range of about 300 microns to about 600 microns. Other sizes may be used as well.

Still referring to FIGS. 10 through 13, third circumferential seal 266 extends along circumferential direction C between third axial seal 254 and first axial seal 244 so that these three seals surround third filter media 260. In addition, when filter 204 is rotated into the third position shown in FIG. 12, seals 244, 254, and 266 surround fluid outlet 242 of receptacle 212. Contact between seals 244, 254, 266 and interior surface 250 of receptacle 212 as shown in FIG. 12 provides fluid sealing that ensures fluid flow—i.e., filtering—is only through third filter media 260. More particularly, fluid received from wash chamber 106 flows into the internal chamber 224 of filter 204 to pass radially outward through only third filter media 260 before exiting through fluid outlet 242 for flow to pump 154. In one exemplary embodiment of the invention, third filter media 260 includes a filter media having pore or hole sizes in the range of about 50 microns to about 150 microns. Other sizes may be used as well.

Accordingly, the exemplary embodiment of FIGS. 10 through 13 allows selection of fluid filtering through a particular filter media during cleaning operations. By way of example, controller 137 might cause motor 234 to rotate filter 204 into the first position during a prewash cycle (when larger particles are present), into the second position during a wash cycle (when large particles may still be present but in smaller amounts and/or sizes than during the prewash), and into the third position during a rinse cycle (when only smaller particles may be present in smaller amounts than in previous cycles). Other methods of operation may be used as well.

FIGS. 14-16 illustrate another exemplary embodiment of the invention in which a second filter 204 is received within receptacle 212 and rotatable about circumferential direction C as previously described. Filter 204 also includes a first filter media 256, a second filter media 258, and a third filter media 260 that are all positioned along cylindrically-shaped wall 226 and adjacent to each other along circumferential direction C.

Filter 204 also includes a first axial seal 270 and a second axial seal 272. Each axial seal 270, 272 extends longitudinally along the axial direction A and has a width that extends along radial direction R towards interior surface 250 of receptacle 212. Filter 204 also includes a circumferential seal 274 positioned at the top 220 of second filter 204. The circumferential seal 274 extends along circumferential direction C between first axial seal 270 and second axial seal 272 so that these three seals surround third filter media 260. In addition, when filter 204 is rotated into the third position shown in FIG. 16, seals 270, 272, and 274 surround fluid outlet 242 of receptacle 212. Contact between seals 270, 272, 274 and interior surface 250 of receptacle 212 as shown in FIG. 16 provides fluid sealing that ensures fluid flow—i.e., filtering—is only through third filter media 260 when filter 204 is rotated into the third position shown in FIG. 16. More particularly, in the third position, fluid received from wash chamber 106 flows into the internal chamber 224 of filter 204 to pass radially outward through only third filter media 260 before exiting through fluid outlet 242 for flow to pump 154. First filter media 256, second filter media 258, and third filter media 260 can have pore or opening sizes as previously described.

Filtering system 200 shown in FIGS. 14, 15, and 16 can be used e.g., with a dishwashing appliance having a first filter 202 operating as previously described. Accordingly, in the first position shown in FIG. 14, some fluid from wash chamber 106 will filter through first filter 202 and be received into receptacle 212 as fluid CF flowing in the gap 268 between interior surface 250 and cylindrically-shaped wall 226. This fluid CF will exit receptacle 212 without flowing through any of filter media 256, 258, or 260. However, in a manner similar to previously described embodiments, some fluid from wash chamber 106 will flow into the internal chamber 224 of second filter 204 and pass through first filter media 256 as flow FF. This flow FF will combine with flow CF from the first filter 202 to exit receptacle 212 through fluid outlet 242 and provide a filtered flow F to pump 154. Accordingly, for the exemplary embodiment of FIGS. 14, 15, and 16, fluid from wash chamber 106 will flow simultaneously through first filter 202 and the first filter media 256 of second filter 204 when in the first position shown in FIG. 14.

When second filter 204 is rotated into the second position shown in FIG. 15, some fluid from wash chamber 106 will filter through first filter 202 and be received into receptacle 212 as fluid CF flowing in the gap 268 between interior surface 250 and cylindrically-shaped wall 226. This fluid CF will exit receptacle 212 without flowing through any of filter media 256, 258, or 260. However, in a manner similar to previously described embodiments, some fluid from wash chamber 106 will flow into the internal chamber 224 of second filter 204 and pass through second filter media 258 as flow FF. This flow FF will combine with flow CF from second filter 204 to exit receptacle 212 through fluid outlet 242 and provide a filtered flow F to pump 154. Accordingly, for the exemplary embodiment of FIGS. 14, 15, and 16, fluid from wash chamber 106 will flow simultaneously through first filter 202 and the second filter media 258 of second filter 204 when in the second position shown in FIG. 15.

Finally, when second filter 204 is rotated into the third position shown in FIG. 16, fluid from wash chamber 106 will only flow through second filter 204 to be filtered through third filter media 260 because of the operation of seals 270, 272, and 274 as previously described. This fluid FF will exit receptacle 212 through fluid outlet 242 without flowing through any of filter media 256 or 258. From fluid outlet 242, filtered flow F is provided to pump 154.

By way of example, for the exemplary embodiment of FIGS. 14 through 16, controller 137 might cause motor 234 to rotate filter 204 into the first position during a prewash cycle (when larger particles are present), into the second position during a wash cycle (when large particles may still be present but in smaller amounts and/or sizes than during the prewash), and into the third position during a rinse cycle (when only smaller particles may be present in smaller amounts than in previous cycles). By allowing a by-pass of flow CF in the first and second position, the embodiment of FIGS. 14 through 16 can be used where more or larger waste particles are anticipated during the cleaning process.

The seals described herein may be constructed from a variety of materials including e.g., flexible rubber materials. However, the seals may also be constructed from more rigid materials including plastics, provided proper tolerances within receptacle 212 are provided for fluid sealing.

Additionally, in each of the embodiments described above, filter 204 is shown as cylindrically-shaped and receptacle 212 is shown as cylindrically-shaped. The axes of these cylindrical shapes are offset to provide the operation described above. Using the teachings disclosed herein, it will be understood that a non-circular or non-cylindrical shape could also be used for receptacle 212. For example, an oblong or elliptical shape for receptacle 212 could also be used.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. 

What is claimed is:
 1. A dishwashing appliance, comprising: a wash chamber having a sump portion; a receptacle located in the sump portion, the receptacle defining an interior surface and a fluid outlet; a pump in fluid communication with the sump portion of the wash chamber to receive fluid from the wash chamber; a first filter positioned in the sump portion and configured for the receipt of fluid circulated through the wash chamber; a rotatable, second filter positioned within the receptacle and configured for the receipt of fluid circulated through the wash chamber, the second filter defining a radial direction, axial direction, and circumferential direction, the second filter rotatable along the circumferential direction within the receptacle, the second filter comprising a cylindrically-shaped wall forming an internal chamber and comprising a first filter media positioned along the cylindrically-shaped wall; a first axial seal and a second axial seal, each extending along the axial direction and each extending radially from the cylindrically-shaped wall of the second filter towards the interior wall of the receptacle; and at least one circumferential seal extending circumferentially between the first axial seal and the second axial seal; and wherein the second filter is rotatable between i) a first position in which fluid from the wash chamber filters simultaneously through both the first filter and the second filter to flow to the pump and ii) a second position in which the seals surround the fluid outlet of the receptacle so that fluid from the wash chamber filters only through the second filter to flow to the pump.
 2. The dishwashing appliance of claim 1, wherein the interior wall of the receptacle is circular in shape.
 3. The dishwashing appliance of claim 1, wherein in the first position the seals do not surround the fluid outlet of the receptacle.
 4. The dishwashing appliance of claim 1, wherein the first filter comprises a grate covering a recess defined in the sump portion of the wash chamber.
 5. The dishwashing appliance of claim 4, wherein the second filter defines a fluid inlet for the flow of fluid into the internal chamber of the second filter, and wherein the fluid inlet for the second filter is at least partially surrounded by the grate.
 6. The dishwashing appliance of claim 1, wherein the interior wall of the receptacle and the second filter form a gap that receives filtered fluid from the first filter.
 7. The dishwashing appliance of claim 1, further comprising at least one controller configured to locate the second filter in the first position during a wash cycle; and locate the second filter in the second position during a rinse cycle.
 8. The dishwashing appliance of claim 1, wherein the second filter comprises a cartridge that is removable from the receptacle.
 9. The dishwashing appliance of claim 1, wherein the first filter is configured with filter openings in the range of about 0.030 inches to about 0.060 inches.
 10. The dishwashing appliance of claim 9, wherein the second filter is configured with filter openings in the range of about 50 microns to about 150 microns.
 11. A dishwashing appliance, comprising: a wash chamber having a sump portion; a receptacle located in the sump portion, the receptacle defining an interior wall and a fluid outlet; a pump in fluid communication with the sump portion of the wash chamber to receive fluid from the wash chamber; a rotatable filter positioned within the receptacle and configured for the receipt of fluid circulated through the wash chamber, the filter defining a radial direction, axial direction, and circumferential direction, the filter rotatable along the circumferential direction within the receptacle, the filter comprising a cylindrically-shaped wall forming an internal chamber and comprising a first filter media, a second filter media, and a third filter media, all positioned along the cylindrically-shaped wall and adjacent to each other along the circumferential direction; a first axial seal, a second axial seal, and a third axial seal, each extending along the axial direction and each extending radially from the cylindrically-shaped wall of the filter towards the interior wall of the receptacle; a first circumferential seal extending circumferentially between the first axial seal and the second axial seal; a second circumferential seal extending circumferentially between the second axial seal and the third axial seal; and a third circumferential seal extending circumferentially between the third axial seal and the first axial seal; wherein the filter is rotatable between i) a first position in which the fluid from the wash chamber filters only through the first filter media to flow to the pump, ii) a second position in which fluid from the wash chamber filters only through the second filter media to flow to the pump; and iii) a third position in which fluid from the wash chamber filters only through the third filter media to flow to the pump.
 12. The dishwashing appliance of claim 11, wherein the interior wall of the receptacle is circular in shape.
 13. The dishwashing appliance of claim 11, wherein in the first position the fluid outlet of the receptacle is surrounded by the first axial seal, the second axial seal, and the first circumferential seal.
 14. The dishwashing appliance of claim 13, wherein in the second position the fluid outlet of the receptacle is surrounded by the second axial seal, the third axial seal, and the second circumferential seal.
 15. The dishwashing appliance of claim 14, wherein in the third position the fluid outlet of the receptacle is surrounded by the third axial seal, the first axial seal, and the third circumferential seal.
 16. The dishwashing appliance of claim 11, wherein the first filter media is configured with filter openings in the range of about 0.030 inches to about 0.060 inches.
 17. The dishwashing appliance of claim 16, wherein the second filter media is configured with filter openings in the range of about 300 microns to about 600 microns.
 18. The dishwashing appliance of claim 17, wherein the third filter media is configured with filter openings in the range of about 50 microns to about 150 microns.
 19. A dishwashing appliance, comprising: a wash chamber having a sump portion; a receptacle located in the sump portion, the receptacle defining an interior wall and a fluid outlet; a pump in fluid communication with the sump portion of the wash chamber to receive fluid from the wash chamber; a first filter positioned in the sump portion and configured for the receipt of fluid circulated through the wash chamber; a rotatable, second filter positioned within the receptacle and configured for the receipt of fluid circulated through the wash chamber, the second filter defining a radial direction, axial direction, and circumferential direction, the second filter rotatable along the circumferential direction within the receptacle, the second filter comprising a cylindrically-shaped wall forming an internal chamber and comprising a first filter media, a second filter media, and a third filter media positioned along the cylindrically-shaped wall; a first axial seal and a second axial seal, each extending along the axial direction and each extending radially from the cylindrically-shaped wall of the second filter towards the interior wall of the receptacle; and at least one circumferential seal extending circumferentially between the first axial seal and the second axial seal; and wherein the second filter is rotatable between i) a first position in which fluid from the wash chamber filters simultaneously through both the first filter and the first filter media to flow to the pump; ii) a second position in which fluid from the wash chamber filters simultaneously through both the first filter and the second filter media to flow to the pump; and iii) a third position in which fluid from the wash chamber flows only through the third filter media to flow to the pump.
 20. The dishwashing appliance of claim 19, wherein in the third position the fluid outlet of the receptacle is surrounded by the first axial seal, the second axial seal, and the circumferential seal. 